Trocar seal system

ABSTRACT

A seal assembly for reception of an elongated surgical instrument is provided which includes a body having at least one opening configured and dimensioned to permit entry of an elongated surgical instrument and defining a central longitudinal axis; a seal member formed of a resilient material and defining an aperture therein, the aperture being configured and dimensioned such that insertion of the surgical instrument into the aperture causes the resilient material defining the aperture to resiliently contact the outer surface of the surgical instrument in a substantially fluid tight manner; and a fabric layer juxtaposed relative to the resilient material. A coating may be applied to the seal member to reduce friction between the seal member and surgical instrumentation inserted therein. The coating is preferably a hydrocyclosiloxane membrane prepared by plasma polymerization process.

BACKGROUND

[0001] 1. Technical Field

[0002] The present disclosure relates to seal systems of the typeadapted to allow the introduction of a surgical instrument into apatient's body. In particular, the disclosure relates to a seal systemto be used in combination with a cannula assembly where the cannulaassembly is intended for insertion into a patient's body and aninstrument is inserted into the patient's body through the cannula.

[0003] 2. Background Of Related Art

[0004] Laparoscopic procedures are performed in the interior of theabdomen through a small incision, e.g., through narrow endoscopic tubesor cannulas inserted through a is small entrance incision in the skin.Minimally invasive procedures are performed elsewhere in the body, e.g.,in the chest, and are often generally referred to as “endoscopic”procedures. Minimally invasive or endoscopic procedures generallyrequire that any instrumentation inserted into the body be sealed, i.e.provisions must be made to ensure that gases do not enter or exit thebody through the endoscopic incision as, for example, in surgicalprocedures in which the surgical region is insufflated. Moreover,endoscopic procedures often require the surgeon to act on organs,tissues, and vessels far removed from the incision, thereby requiringthat any instruments used in such procedures be relatively long andnarrow.

[0005] For such procedures, the introduction of a tube into certainanatomical cavities such as the abdominal cavity is usually accomplishedby use of a system incorporating a trocar and cannula assembly. Acannula assembly is formed of a cannula attached to a cannula housingwhich generally includes seal assembly adapted to maintain a seal acrossthe opening of the seal assembly both with and without an instrumentinserted therethrough. Since the cannula is in direct communication withthe internal portion of the seal assembly, insertion of the cannula intoan opening in the patient's body so as to reach the inner abdominalcavity should be adapted to maintain a fluid tight interface between theabdominal cavity and the outside atmosphere.

[0006] Since minimally invasive surgical procedures in the abdominalcavity of the body generally require insufflating gases to raise thecavity wall away from vital organs, the procedure is usually initiatedby use of a Verres needle through which a gas is introduced into thebody cavity. The gas provides a slight pressure which raises the wallsurface of the peritoneum away from the vital organs thereby providingan adequate region in which to operate. Thereafter, a trocar assemblywhich includes a cannula and a trocar or obturator is inserted withinthe cannula to puncture the peritoneum, i.e. the inner lining of theabdominal cavity wall. The obturator is removed and laparoscopic orendoscopic surgical instruments may then be inserted through the cannulato perform surgery within the abdominal cavity. The cannula may also beutilized for introducing tubes into the body as for drainage purposes,for specimen removal, for diagnostic evaluations, or the like.

[0007] In view of the need to maintain the atmospheric integrity of theinner area of the cavity, a seal assembly for a cannula which permitsintroduction of an obturator and a wide range of surgical instrumentsand which maintains the atmospheric integrity of the inner area of thecavity is desirable. Generally, in the context of insufflatory,minimally invasive surgical procedures, cannula assemblies includestructure(s) that satisfy two sealing requirements. The firstrequirement is to provide a substantially fluid tight seal when aninstrument is not present in the cannula. The second requirement is toprovide a substantially fluid tight seal when an instrument is beingintroduced into or already is present in the cannula. In this regard,there have been a number of attempts in the prior art to provide suchsealing requirements.

[0008] U.S. Pat. No. 4,655,752 to Honkanen et al. teaches a cannulaincluding a housing and first and second seal members. The first sealmember is conically tapered toward the bottom of the housing and has acircular opening in its center, while the second seal is conicallytapered and cup shaped. The second seal includes at least one slit toallow for the passage of instruments.

[0009] U.S. Pat. No. 4,929,235 to Merry et al. teaches a self-sealingcatheter introducer having a sealing mechanism to prevent blood or fluidleakage. The sealing mechanism includes a planar sealing element havinga slit and a conical sealing element. The sealing elements are eachadapted to surround a tube.

[0010] U.S. Pat. Nos. 4,874,377 and 5,064,416 to Newgard et al. relateto a self-occluding intravascular cannula assembly in which anelastomeric valving member is positioned transversely to a housing andis peripherally compressed to cause displacement, distortion and/orrheological flow of the elastomeric material. A frustoconical dilatorprojection cooperates with the elastomeric valving member in moving thevalving member to a non-occluding position.

[0011] U.S. Pat. No. 5,300,033 to Miller suggests a valve constructionincluding an elastic body having a cylindrical wall with first andsecond walls formed integrally with the cylindrical wall. The secondwall includes a slit to permit passage of a surgical instrument andfirst and second leaflets which define the slit. The leaflets arethicker in cross section to provide an additional closing force at theslit.

[0012] A disadvantage of several known seal systems for cannulasconcerns the difficulty encountered in inserting and advancing thesurgical instrument through the seal unit. In particular, since knownelastomeric seal members are designed to form and maintain a fluid tightseal about the instrument, the aperture or slit within the seal throughwhich the instrument is passed is of relatively small or narrowdimension. Further, portions of the seal member defining the apertureare generally thick in cross-section to provide a sufficient closingforce of the seal about the instrument. see, e.g., U.S. Pat. No.5,300,033. As a consequence of these design considerations, the level offorce needed to insert and advance the instrument through the sealaperture is increased, thereby requiring awkward maneuvering on thesurgeon's behalf to appropriately position the instrument for thedesired surgery. Moreover, known seal systems are generally ineffectualin accommodating instruments of differing diameter while maintainingacceptable insertion forces and facilitating the range of desiredsurgical manipulations, e.g., angular instrument movements and specimenremoval.

[0013] Accordingly, the present disclosure obviates the disadvantages ofthe prior art by providing a seal unit or assembly for a cannulaassembly, which is capable of forming and maintaining a tight seal aboutinstruments of varying diameters inserted through the cannula and whichincorporates structure to enhance and facilitate passage of theinstrument through the seal unit.

SUMMARY

[0014] The present disclosure provides a seal assembly for reception ofan elongated surgical instrument, which comprises a body having at leastone opening configured and dimensioned to permit entry of an elongatedsurgical instrument and defining a central longitudinal axis; a sealmember formed of a resilient material and defining an aperture therein,the aperture being configured and dimensioned such that insertion of thesurgical instrument into the aperture causes the resilient materialdefining the aperture to resiliently contact the outer surface of thesurgical instrument in a substantially fluid tight manner; and a fabriclayer juxtaposed relative to the resilient material.

[0015] The seal assembly may further include a coating applied to theseal member to reduce friction between the seal member and surgicalinstrumentation inserted therein. The coating is preferably ahydrocyclosiloxane membrane prepared by plasma polymerization process.

[0016] In one aspect of the presently disclosed seal assembly a ringmember is secured to the seal member and includes a dampening elementdisposed between a surface of the ring member and a surface of the body.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various embodiments are described herein below with reference tothe drawings wherein:

[0018]FIG. 1 is a perspective view of one embodiment of a seal assemblyconstructed in accordance with the present disclosure;

[0019]FIG. 2 is a perspective view with parts separated showing thevarious structural components of the seal assembly embodiment of FIG. 1;

[0020]FIG. 3 is a perspective view of a fabric portion for incorporationinto the seal element of the embodiment of FIG. 1;

[0021]FIG. 4 is a cross-sectional view taken along section line 4-4 ofFIG. 3;

[0022]FIG. 5 is a perspective view of a fully formed seal member for theseal assembly of FIG. 1;

[0023]FIG. 6 is a cross-sectional view taken along section line 6-6 ofFIG. 5;

[0024]FIG. 6A is an alternative embodiment of the seal element of FIG.6;

[0025]FIG. 7 is a cross-sectional view of the seal assembly of FIG. 1;

[0026]FIG. 8 is a perspective view of a trocar assembly having the sealassembly of FIG. 1 removably installed thereon;

[0027]FIG. 9 is a partial cross-sectional view showing the seal bodyhousing taken along section line 9-9 of FIG. 8;

[0028]FIG. 10 is an alternative embodiment of the seal assembly of thepresent disclosure;

[0029]FIG. 11 is a cross-sectional view of a further embodiment of theseal assembly constructed in accordance with the present disclosure;

[0030]FIG. 12 is a perspective view of the seal assembly of FIG. 11;

[0031]FIG. 13 is a perspective view with parts separated of the sealassembly embodiment of FIG. 11;

[0032]FIG. 14 is a cross-sectional view of a further embodiment of theseal assembly constructed in accordance with the present disclosure; and

[0033]FIG. 15 is a perspective view of the seal member of the sealassembly of FIG. 14.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] Referring now in detail to the drawing figures in which likereference numerals identify similar or identical elements, a firstembodiment of the seal assembly of the present disclosure is illustratedin FIGS. 1-9, and is designated generally as seal assembly 100.

[0035] The presently disclosed seal assembly embodiments contemplate theintroduction of various types of surgical instruments adapted forinsertion through an elongated trocar assembly. Examples of suchinstruments include clip appliers, graspers, dissectors, retractors,staplers, laser fibers, photographic devices, endoscopes andlaparoscopes, tubes, and the like. Such instruments are collectivelyreferred to herein as “instruments”.

[0036] Referring to FIG. 2, seal assembly 100 includes a seal member 118disposed within the seal assembly body or housing components 114 and 116which snap fit together by way of flexible tab portions 114 a beingdeflected upon insertion into receiving openings (not shown) formed inhousing component 116. Seal member 118 has a circular array of holesformed therethrough around the periphery of an inner section 118 b.

[0037] A two part ring assembly which includes ring members 120 and 122are snap fitted together on either side of seal member 118. Ring member120 is disposed adjacent the distally facing surface of seal member 118and ring member 122 is disposed on the proximally facing side of sealmember 118. Ring 120 is provided with holes 120 a and posts 120 b whichare alternately disposed around the ring and are aligned with holes 118a on seal member 118. Ring 122 is provided with posts 122 a and holes122 b which mate with holes 120 a and posts 120 b of ring member 120,respectively by snap fitting together thereby surrounding inner section118 b. Although rings 120 and 122 are shown having alternating holes andposts, one of the rings could have all holes formed therein while theother ring could have all posts aligned with the holes of the otherring. Additionally, greater or fewer holes and posts may be utilized tosecure the two rings together.

[0038] A seal clamp 124 is provided within the housing component 114 and116 and serves to secure the outer periphery of seal member 118 withinseal assembly 100 (as best shown in FIG. 7). Seal clamp 124 is providedwith four projecting posts 124 a which fit within openings (FIG. 7)formed on the proximal side of lower housing 116. Seal clamp 124 alsoserves to secure a proximal flange of a lower seal 126 which is providedat the distal end of lower housing member 116. Lower seal 126 assists inthe securement of seal assembly 100 to cannula assembly 110.

[0039] Referring now to FIGS. 3-6, seal member 118 includes a fabricdisc-shaped portion 128 which is preferably disposed on both theproximal and distal sides of inner section 118 b of seal member 118.Alternatively, fabric section 128 may be disposed on just one of eitherthe proximally facing surface or the distally facing surface of innerportion 118 b, as desired. Fabric portion 128 may be of any suitablefabric, for example, a SPANDEX material containing 20% LYCRA availablefrom Milliken.

[0040] In one method of forming the composite seal member 118 withfabric portion 128 a raw, i.e., uncured polyisoprene plug is firstcompressed into a flat state, e.g., a flat sheet of polyisoprene. Asingle layer of fabric is positioned on top of the flattenedpolyisoprene sheet and compressed into the uncured rubber by anysuitable compression process such as, for example, calendering. If it isdesired to have fabric on both sides of seal member 118, this process isrepeated on the other side of the polyisoprene sheet. The fabricpolyisoprene composite is die cut into circular slugs having an outerdiameter and an inner diameter which forms a central aperture. The slugsare placed in a hot compression mold to cure the polyisoprene. This stepalso serves to extrude the outer portions of seal member 118 whichextend outwardly from inner section 118 b.

[0041] During the above-described process the bleed-through of thepolyisoprene material into and/or through the fabric layers is regulatedby the density of the fabric selected. A greater degree of bleed-throughof polyisoprene provides greater resistance to fraying of the fabricupon repeated insertion of instruments through the seal. However, toomuch bleed-through of the polyisoprene through the fabric will increasefriction forces upon instruments being inserted through seal member 118.

[0042] Referring to FIG. 6A, an alternative embodiment of seal member118 is shown as seal member 418. Seal member 418 is the same as sealmember 118 in most aspects except that inner section 418 b is formed tohave fabric layer 428 enveloped between upper and lower polyisoprenelayers 418 c and 418 d.

[0043] In order to reduce friction between instruments and the sealmember, e.g. seal member 118 or seal member 418, as instruments areinserted through seal assembly 100, a coating may be applied to the sealmember. One coating which has been found particularly effective is ahydrocyclosiloxane membrane prepared by plasma polymerization process.Such a coating is available from Innerdyne, Inc. of Salt Lake City,Utah, U.S.A., and is disclosed in U.S. Pat. No. 5,463,010 which issuedto Hu et al. on Oct. 31, 1995, the entire contents of which are herebyincorporated by reference.

[0044] Referring to FIGS. 7 and 8, seal assembly 100 is used incombination with a conventional trocar assembly which includes a cannulaassembly 110 and a trocar obturator 112. Examples of trocar assembliesin which the present seal assembly may be utilized are disclosed in U.S.Pat. No. 5,603,702 which issued on Feb. 18, 1997 to Smith et al. andU.S. application Ser. No. 08/546,009 filed Oct. 20, 1995 by Smith etal., the entire contents of each of these disclosures are herebyincorporated by reference.

[0045] Seal assembly 100, either alone or in combination with a sealunit/seal assembly internal to cannula assembly 110, provides asubstantial seal between a body cavity of a patient and the outsideatmosphere both during and subsequent to insertion of an instrumentthrough the cannula. In this manner, insufflation gases are preventedfrom escaping through the trocar assembly to the outside environment.Seal assembly 100 is capable of accommodating instruments of varyingdiameter, e.g., from about 5 mm to about 12 mm, while providing a fluidtight seal with the outer diameter of each instrument. The versatilityof the presently disclosed seal assembly embodiments greatly facilitateendoscopic surgery, wherein a variety of instruments having differentdiameters are often needed during a single surgical procedure.

[0046] Seal assembly 100 is preferably detachably mountable to theproximal end of cannula assembly 110. Thus, the surgeon can remove theseal assembly 100 from the cannula assembly 110 at any time during thesurgical procedure and, similarly, mount the seal assembly 100 to thecannula when desired in order to provide a sealing engagement with aninstrument to be inserted through the cannula. In addition, sealassembly 100 may be readily adapted for mounting to conventionalcannulas of differing structures. The detachability of seal assembly 100from cannula assembly 110 facilitates specimen removal through cannulaassembly 110. Seal assembly 100 includes a housing which is formed bythe snap fitting together of end cap 114 and lower housing member 116.Preferably the housing components of seal assembly 100 are formed of apolycarbonate material such as ABS available from the General ElectricCompany.

[0047]FIG. 9 shows an instrument having a shaft 130 inserted throughseal assembly 100 and a duck bill valve or “zero” seal valve 132 whichprevents the escape of insufflation gases in the absence of aninstrument in the trocar assembly. As shown in FIG. 9, seal member 118provides a seal about the periphery of shaft 130.

[0048] Referring to FIG. 10, an alternate embodiment of seal assembly100 is designated generally as seal assembly 150. Seal assembly 150 isthe same as seal assembly 100 except that an inner planar seal member152 is disposed in the distal end of seal assembly 100 to provideadditional sealing capability for instruments having larger diameters.Seal element 152 has an aperture 154 which has a diameter larger thanthe diameter of aperture 156 of seal member 118. A further featureillustrated in FIG. 10 is a dampening member such as pad 158 which issecured to the proximal surface of ring 122 to dampen the sound createdby the impact of the proximal surface of ring 122 with the inner distalfacing surface of housing component 114. Other dampening memberconfigurations are also contemplated. For example, ring 122 may beover-molded with material such as polyisoprene so as to envelope part orall of the ring thereby forming a bumper between the ring and thehousing component.

[0049] Referring to FIGS. 11-13, a further embodiment of a seal assemblygenerally designated as seal assembly 200 is shown throughout theseveral views. Seal member 218 is configured in an hourglass shape andpreferably includes the fabric portion 228 formed as part of seal member218 in a similar manner as described above. The friction reducingcoating of a hydrocyclosiloxane membrane prepared by plasmapolymerization process noted above may also be utilized to coat thesurfaces of seal member 218.

[0050] Referring now to FIGS. 14 and 15, a further embodiment of theseal assembly generally designated as seal assembly 300 is shown. Sealmember 318 is similar to seal member 118 except that inner portion 318 bis formed in a conical shape with a wider opening directed towards aproximal end of seal assembly 300 and a narrower opening directedtowards distal end of seal assembly 300. The friction reducing coatingof a hydrocyclosiloxane membrane prepared by plasma polymerizationprocess noted above may also be utilized to coat the surfaces of sealmember 318.

[0051] It will be understood that various modifications may be made tothe embodiments shown herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications ofpreferred embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the presently disclosedseal assemblies.

What is claimed is:
 1. A seal assembly for reception of an elongatedsurgical instrument, which comprises: a body having, at least oneopening configured and dimensioned to permit entry of an elongatedsurgical instrument and defining a central longitudinal axis; a sealmember formed of a resilient material and defining an aperture therein,the aperture being configured and dimensioned such that insertion of thesurgical instrument into the aperture causes the resilient materialdefining the aperture to resiliently contact the outer surface of thesurgical instrument in a substantially fluid tight manner; and a fabriclayer juxtaposed relative to the resilient material.
 2. A seal assemblyfor reception of an elongated surgical instrument according to claim 1,which further comprises a coating applied to the seal member to reducefriction between the seal member and surgical instrumentation insertedtherein.
 3. A seal assembly for reception of an elongated surgicalinstrument according to claim 2, wherein the coating is ahydrocyclosiloxane membrane prepared by plasma polymerization process.4. A seal assembly for reception of an elongated surgical instrumentaccording to claim 1, which further comprises a ring member secured tothe seal member and having a dampening element disposed between asurface of the ring member and a surface of the body.